Good game, bad internet connection

Its a really good game. And I enjoyed it. However the game has a really serious connection error. I just download game about 1 hour and play it. After second time, i cant login my account anymore. It just keeps showing connection failed. But the internet is totally working good in my place. Now I dont know what should I do.

AppleWilliam about DJMAX RAY by Neowiz, v1.0.11